Controlling devices, that is, for example, remote controls capable of commanding operation of features and functions of consumer electronic appliances such as TVs, audio receivers, set top boxes, home automation systems, and the like, are well known in the art and have become a ubiquitous part of the modern home. Increasingly, the utility of these devices is being enhanced by providing for two-way communication between a controlling device and at least one of the controlled appliances.
A historically preferred communication medium for such controlling devices is infrared, since this technology is relatively inexpensive, does not radiate outside of the user's immediate environment, and has proven reliable in existing unidirectional and low data rate applications. However, newer display technologies such as plasma TV screens are themselves strong sources of infrared radiation and may be problematic during two-way infrared-based communication between a controlling device and an appliance, in particular with respect to the infrared receiver in the controlling device which is likely to be pointed directly toward the vicinity of the TV screen while in use.